The present invention relates to an electrical connector for flexible flat cable or flexible printed circuit boards.
Typical electrical connectors for flexible flat cables (FFC) or flexible printed circuit boards (FPC) comprise an insulating or dielectric housing having an insertion aperture for the foil with printed conductors embedded therein. A plurality of foil contacts is mounted in the housing along this insertion aperture. The foil contacts are substantially arranged parallel to one another. Contact sections of these foil contacts are arranged in the insertion aperture in such a way that they can contact conductive areas of the foil cable. The housing also often comprises an actuator (pressure clamp) which can be moved from an xe2x80x9copenxe2x80x9d state in which the foil can be inserted into the insertion aperture, into a xe2x80x9cclosedxe2x80x9d state in which the foil and the connections thereof are pressed against the contact region of the foil contact.
Many of the above-described electrical connectors for FFC/FPC foils are designed in such a way that the foil can be inserted with zero insertion force. When the actuator is in the xe2x80x9copenxe2x80x9d position then the foil can be pushed into the insertion aperture without using force. If the actuator is then closed the foil is grasped and the printed conductors of the foil are pressed against the contact sections of the foil contact.
However, electrical connectors of this type often exhibit defective electric connections or electric connections which are susceptible to faults as the foil can slip during assembly or operation.
One potential application of these electrical connectors is in the motor vehicle electronics sector where, because the extremely harsh environmental conditions the electric contact has to satisfy very high requirements, in particular in relation to resistance to vibration and corrosion but also thermal stability and current handling capability. Furthermore, the electrical connector should be inexpensive to produce and be able to be miniaturised as far as possible.
European patent specification EP 0 696 090 B1 describes an electrical connector for flexible printed circuit boards which is assembled on a further printed circuit board. The connector comprises a housing with an insertion aperture and a plurality of contact elements which are arranged in the housing in such a way that spring contact components of the contact elements project into the insertion aperture. A bearing region is provided on the contact element. An actuator which can be rotated on the bearing region from an open position into a closed position, has a pressure edge which, when the actuator is moved into the closed position, moves in the direction opposite to the insertion direction of the foil and presses the foil against the spring contact component. In this way, the electric connections between the foil and the contact elements are produced.
A connector for printed circuit boards, in particular for flexible printed circuit boards such as FPC or FFC, is the subject of the European patent application EP 0 926 778 A2. The connector has an insulating housing with a groove which is open at the top and base contacts which are arranged in the housing at regular intervals and each have a resilient bar and an integral arm adjoining thereto. Each bar has a conductive projection which protrudes into the groove and each arm, which extends along the top of the housing into the groove, has a pivotal end opposing the projection. An insulated press-on cover engaging in the pivotal ends can be rotated between a closed position close to the projections and an open position remote from the projections. The pivotal ends lock the cover and press the flexible printed circuit board against the resilient bars. The cover comprises cover contacts which rotatably engage in the pivotal ends and correspond with the base contacts, so the pivotal ends, the covering contacts and the flexible printed circuit contact one another electrically when the cover is closed.
A further electrical connector for flat circuits is described in the European Patent Publication EP 0 966 070 A1. The connector comprises a dielectric housing with an insertion aperture and a plurality of electrical connections which are mounted in the housing and are arranged along the insertion aperture. The connections have contact regions in order to contact the printed conductors of the flat circuit. An actuator is movably mounted on the housing and changes its position between an open position in which the foil can be inserted and a closed position in which the foil and its printed conductors can be pressed against the contact regions of the connections. Only some of the connections comprise restraining connections with gripper elements which grip and fix the flat circuit when the actuator is open. Other connections do not contain any restraining elements, so the foil can be inserted here without insertion force.
Finally, U.S. Pat. No. 4,082,402 discloses a connecting terminal for a crimp connection when connecting flexible printed conductors. The connecting terminal is designed in such a way that it penetrates the insulating sheath of the flexible printed conductor and surrounds the printed conductor in order to provide both a mechanical and electrical connection thereto. The connecting terminal has two pairs of sharp teeth located opposite one another which after penetration of the foil are bent with respect to one another in such a way that they surround the printed conductor and electrically contact it. In an electrical connector for flexible flat cable which uses a plurality of connecting terminals of this type both the electric contacting and the tension relief of the flexible foil are therefore ensured by the sharp teeth of the connecting terminal.
All these connectors exhibit the drawback that, on the one hand, their production is very complex and therefore expensive and, on the other hand, that contacting of the foil printed conductor is not reliable enough under extreme environmental conditions.
An object of the present invention therefore is to provide an electrical connector for a foil with printed conductors embedded therein which ensures reliable contacting and, moreover, permits inexpensive production and simplified assembly of the component.
The present invention relates to an electrical connector which at least partially receives a foil with printed conductors embedded therein, and comprises an insulating housing with an insertion aperture for the foil and at least one foil contact with a contact section for contacting the printed conductors. The foil contact has a connection section for connection to an electric component and an actuating zone to receive mechanical pressure. To ensure reliable contacting and inexpensive production and simplified assembly of the components, the foil contact is bent as one piece from a punched spring sheet and has at its first contact arm an end section which is bent approximately to a U-shape, which can be brought into contact with the two contact arms by mechanical pressure. According to the invention, the connector also comprises an actuator to actuate this foil contact in which retaining webs are integrally formed which penetrate the foil when the actuator is closed. Finally, a connector is proposed in which the housing comprises a connector part and a collar part separated therefrom.